Combine the flour, 1/4 cup sugar and salt in a bowl and mix
well. Cut in the butter until crumbly. Pat over the
bottom of a 9x13-inch baking pan.
Bake at 350 degrees for 15 to 18 minutes or until light
brown.
Remove to a wire rack to cool.
Combine 1 cup sugar and cornstarch in a saucepan and mix
well. Add the raspberries. Bring to a boil, stirring
constantly.
Boil until thickened, stirring constantly. Cool slightly.
Spoon over the baked layer.
Chill in the refrigerator.
Combine the marshmallows and milk in a saucepan.
Cook over low heat until blended, stirring constantly.
Remove from heat. Fold in the whipped cream. Spread
over the prepared layers.
Chill until serving time.